Cryopreservation in Eukaryotes

Since accidentally discovering the ability of glycerol on protecting cells from freezing damage, many researchers have been pursuing to develop cryopreservation methods of a very wide range of cells and some tissues, and these have found widespread applications in biology and medicine. From the point of view of living organisms, cryopreservation is a useful tool for ex situ conservation of genetic resources together with its contribution on conservation of their biodiversity. Cryopreservation in Eukaryotes includes totally 12 chapters, which have been written by the expert researchers in the field. The chapters are a comprehensive collection of the most frequently used methods for eukaryotes. With this book, every researcher will better understand the principles, background, and current status of cryopreservation in particular organisms. Studies on semen cryopreservation in Brazilian freshwater fish have been growing in number of publications and investigated species. Despite this apparent increase in research, standardization of cryoprotocols is still missing, making it clear that the grounds on the quality of cryopreserved semen has not yet reached a level that guarantee satisfactory results for its replication. This chapter aims to make a critical and reflective analysis on the ways cryopreservation of freshwater fish semen has been conducted in Brazil. The difficulties in standardizing protocols, broodstock, and selection of genetically superior animals; the barriers in transferring technology from laboratory benches to the field and make feasible the use of cryopreserved semen on a commercial scale; the formation of germplasm banks and the responsible use of cryopreserved material are also discussed. We have no intention to point out the successes and mistakes that may have been committed in pursuing development of cryopreservation protocols, but a reflection on the future directions considering what should be pondered on this subject with objectivity and scientific consolidation Many native orchid populations declined yearly due to economic development and climate change. This resulted in some wild orchids being threatened. In order to maintain the orchid genetic resources, development of proper methods for the long-term preservation is urgent. Low temperature or dry storage methods for the preservation of orchid genetic resources have been implemented but are not effective in maintaining high viability of certain orchids for long periods. Cryopreservation is one of the most acceptable methods for long-term conservation of plant germplasm. Orchid seeds and pollens are ideal materials for long-term preservation (seed banking) in liquid nitrogen (LN) as the seeds and pollens are minute, enabling the storage of many hundreds of thousands of seeds or pollens in a small vial, and as most species germinate readily, making the technique very economical. This article describes cryopreservation of orchid genetic resources by desiccation and a case study of Bletilla formosana. We hope to provide a more practical potential cryopreservation method for future research needs